Manufacture of cast-steel.



UNITED STATES MAURICE MESLANS,

Patented July 26, 1904.

OF PARIS, FRANCE.

MANUFACTURE OF CAST-STEEL.

SPECIFICATION forming part of Letters Patent No. 765,932, dated July 26,1904.

Application filed July '7, 1902. Serial No. 114,651. (No specimens.)

To all whom, it may concern:

Be it known that I, MAURIon MESLANS, a citizen of the Republic ofFrance, and a resident of Paris, France, have invented Improvements inthe Manufacture of Cast-Steel, of which the following is aspecification.

It is known that the bubbles which occur in greater or less quantity inthe pieces or ingots of cast-steel are due principally to the presenceof three gasesoxid of carbon, hydrogen, and nitrogenwhich are dissolvedin the mass and which separate out at the moment of solidification ofthe metal. This drawback has been removed in a certain degree by theaddition to the metallic bath at the moment of casting of a smallquantity of aluminium. The action of this metal is to decompose the oxidof carbon, and it thus causes one of the three objectionable gases todisappear; but it has no action on the hydrogen and on the nitrogen,and, further, when the gaseous mixture evolved from steel cast with theaddition of aluminium is analyzed only a small percentage of oxid ofcarbon is found, while from fifty to eighty per cent. of hydrogen andfifteen to forty-five per cent. of nitrogen occur. Consequently in orderto remove the hydrogen and nitrogen from the steel it is necessary toemploy two metals capable of forming'with these gases stable compoundsat a high temperature. The metals such as calcium, barium, strontium,and lithium possess this property; but their use in the state of thepure metals is impossible in practice because of their high price and ofthe difficulty of obtaining them in sufficient quantities. 1 havediscovered, however, that these very metals are capable of uniting withaluminium in proportions which may be Varied as desired in such a waythat in an aluminium-calcium alloy, for example, the

calcium adds its action to that of the aluminium to eliminate thedissolved gases, forming with the hydrogen and nitrogen fixed or stablehydrids and nitrids. By the use of these compounds I obtain a new,practical, and eflicacious process, by which it is possible to producesteel cleared from bubbles.

The addition of a small quantity of alloy to a bath of molten steeltakes its eifect at the moment of casting in the same manner as haspreviously been done when using aluminium. The proportion to be usednaturally varies with the composition of the alloy, in which theproportion of calcium may range between five and ninety-five per cent.It varies also according as the steel is produced in a reverberatoryfurnace or by the Bessemer process. Further, in order to efiect thethorough contact of the alloy with the bath of metal it is onlynecessary to follow the course of action employed hitherto with purealuminium.

I am not aware that any one has heretofore formed such an alloy as 1have herein described, and I wish to be understood as reserving all myrights in such alloy or method of making it as inventions for which Ihave filed a divisional application, Serial No. 206,161, filed May 3,1904.

I claim as my invention- The herein-described process for removingoxygen, nitrogen and hydrogen from steel in the process of casting,consisting in incorporating with the molten steel an alloy of aluminiumand calcium.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

MAURICE MESLANS.

Witnesses:

ALPHONSE MIJEAN, EDWARD P. MAOLEAN.

